No doubt arson was involved, that is no surprise. Most large catastrophic fires have elements of arson involved. Businesses under financial stress and heavily insured are extremely prone to fires. On a high fire danger day, several businesses may light up at the same time. They may have hired the same team of arsonists. A few other historically fire prone places may also light up to try to make it look like the fires occurred naturally.
Odds are the arsonists had a high level of fire theory training. Not terribly difficult to identify likely suspects. Any of those who suddenly came into alot of money and started spending like they did would be people to examine very closely. Also be on the lookout for corrupt police that were turning a blind eye to the developing situation.
